1. Field of the Invention
The present general inventive concept relates to a liquid composition to clean a nozzle of an inkjet printer, and more particularly, to a liquid composition to remove impurities from a nozzle surface of an inkjet printer, and a cleaning unit using the same.
2. Description of the Related Art
Recently, as demands for inkjet printers have continuously increased, many research studies have been conducted to improve the printing quality and reduce the manufacturing costs of such printers. Inkjet printers are used in a wide range of applications, including advertisement broadcasting industries or advertisement businesses.
As for image processing, a variety of methods of colorizing a hard copy are developed due to high demand for colored hard copies. Such methods include a dye-sublimation printing method, a thermal wax transfer printing method, an inkjet printing method, an electrophotographic printing method, and a thermally processed silver printing method.
In the inkjet printing method, an ink droplet is ejected from a nozzle of a printing head of an inkjet printer on a printing medium, such as paper sheet, thereby forming dots which form letters or images. The inkjet printing method is less expensive than other printing methods and high-quality color images can be printed using this method. Ink used in the inkjet printing method is prepared by dissolving or dispersing water-soluble dye or pigment in a solvent including water and a water-soluble organic solvent. When required, the ink may further include a surfactant.
Inkjet printers which are operated using the inkjet printing method can be categorized into a piezoelectric-type inkjet printer which ejects ink using a piezoelectric device and a thermal-type inkjet printer which ejects ink using a thermal device, according to a method of ejecting ink droplets.
Meanwhile, ink contained in an ink chamber of an inkjet printer head is locally evaporated by a heating device to generate bubbles, and thus an ink droplet in the ink chamber is ejected on a printing medium through an orifice, such as a nozzle. Therefore, a thermal-type inkjet printer includes an inkjet printer head, including a heating device which heats ink and is positioned in the ink chamber, and an operating circuit, such as a logic integrated circuit, operating the heating device.
Much research into ink is being carried out to improve an output speed of inkjet printers and the clarity and brightness of an image. For example, a pigment ink can be used for inkjet printing to increase the printing speed, to obtain a clear color, and to improve waterfastness of black ink. Pigment ink and dye ink should dry quickly on a paper medium. However, quick drying may cause clogging in an inkjet printer head. Specifically, clogging can be caused by ink, dust, or paper. A solid material formed by clogging a nozzle surface cannot be removed and may affect the quality of a printed image. Such clogging is referred to as “nozzle clogging.” When nozzle clogging or nozzle wetting occurs, ink ejection is hindered and thus the ejection speed of ink is decreased and it is difficult for an ink droplet to be ejected.
However, conventional methods of removing impurities from a nozzle surface do not entirely remove impurities remaining on the nozzle surface and use a general cleaning composition. Therefore, an optimized cleaning function cannot be obtained.